plastic mold company

ribs of plastic part

Gussets_Radii_RibsTo ensure strength and rigidity ,but without increase the wall thickness of the plastic parts ,we could add some reinforcing ribs on the appropriate parts area , which not only avoid deformation of plastic parts , in some cases , but also improve plastic melt movement of plastic molding .In order to increase the strength and rigidity of the plastic parts , the number of the ribs should be increased , in stead of increasing the wall thickness.Without increasing the wall thickness of the article, the ribs could enhance the strength and rigidity of part in order to save the usage of material and reduce weight and cost.The ribs could overcome the deformation caused by the uneven stress for the different wall thickness of molded part.

The basic design principle

Ribs ( enforce ribs ) on the plastic parts are function parts.Effectively, ribs shape could increased rigidity and strength without a significant increase in product  section area ,it is especially suitable for plastic part often subject to pressure , torsion , bending condition . In addition, the ribs but also serve as an internal flow channel, and will help fill the cavity of the plastic mold and increase the flow among the junction area of plastic part.
ribs are generally placed on non-contact surface of plastic products , its direction should follow the direction of maximum stress and maximum offset  ,  location of the ribs  has  some limited considerations on the subject , such as cavity filling, shrink and Stripping and so on.

The length of the ribs may be same as the length of the product  , or occupies only part of the length of the product for locally increasing the rigidity of that portion of the product . If the product outer ends are not connected to the ribs , it should not be abruptly terminated by the ribs , the rib height should be gradually reduced until the 0, and thus reduce the occurrence of trapped gas, short shot , burns and other problems that often happen in the  insufficient venting or closed position.

The most simple form of the ribs is a rectangular column attached on the surface of the product , but in order to meet  production or structural considerations on the shape and size of the products,  sometimes ribs must be changed .